


what happens tomorrow morning? **REUPLOAD**

by chocco_chaud



Category: Undertale (Video Game)
Genre: Author Is Sleep Deprived, Bottom Papyrus (Undertale), Brotherly Love, Dead Dove: Do Not Eat, Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Vagina (Undertale), First Time, Gay Sex, I Wrote This Instead of Sleeping, Innocence, Loss of Virginity, M/M, Non-Consensual, Not Beta Read, Rough Sex, Sibling Incest, Sleep Sex, Top Sans (Undertale), Undertale Saves and Resets, Virginity, at some point!!, does that tag apply? is this gross enough for that tag?, i just can't right now, pretty awful shit from what i remember lmao, that's up to you, will edit this
Language: English
Status: Completed
Published: 2021-01-19
Updated: 2021-01-19
Packaged: 2021-03-17 13:07:25
Rating: Not Rated
Warnings: Rape/Non-Con
Chapters: 1
Words: 3,470
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28849557
Author URL: https://archiveofourown.org/users/chocco_chaud/pseuds/chocco_chaud
Summary: with all he knows about the resets, sans finds it difficult to control himself, unfortunately for his sleeping brother papyrus ;;**this is a reupload of a fic i posted like a week ago!! i took it down so i could edit it, but stuff got real busy so i figured i'd just post it again now and edit it when i had the chance. i hope you have fun, and please let me know if there's anything major that needs to be edited right away lol, i didn't see anything when i skimmed but then again i am an idiot!**do enjoy!!
Relationships: Papyrus/Sans (Undertale)
Comments: 9
Kudos: 41





	what happens tomorrow morning? **REUPLOAD**

**Author's Note:**

> have fun!!

Sans was hard already, and he hadn’t even laid a finger on Papyrus, or himself, yet. Fucking rock hard, stupid blue cock glowing softly through his thin shorts as he stood there in the middle of the night, silent, frozen, watching his brother sleep. 

Jesus, he was pathetic.  _ What am I doing? _

All it took was the sight of him. A beautiful sight, long, lanky bones all stretched out under his thin covers, mouth open just-so-slightly, broad ribcage slowly rising and falling with each soft breath. His collarbone, curved and sharp, just barely peeking out from underneath those ridiculous pajamas he wore every night, those elegant fingers, thin and precise, resting on his pillow, nearly completely obscuring the view of that pretty face of his. 

Fuck.  _ Fuck. What are you doing? _

Sans had been staring for almost 10 full, silent minutes now, tired war waging inside him between what little remained of his morals and, well, the rest of him. He’d been planning; or at least fantasizing; about this, about his _brother,_ for weeks. Months, even. The urge had proved impossible to repress.

And what did it matter, anyways, right? Even if Papyrus ended up remembering this at all, he wouldn’t remember it for very long, anyways. Neither would Sans (he sometimes wondered if he'd already done this before and just forgotten, which was… chilling), not after the next reset. So why not? 

_ Because he’s your brother, you sick fuck,  _ his conscious screamed, outraged, even as he shuffled forward, mere inches, now, from Papyrus’s sleeping form,  _ you should want to protect him. Keep him safe. This is disgusting. _

Sure, but who cares? It doesn’t matter. None of it matters. Sans could go on a fucking murder spree and it wouldn’t matter, because the fucking anomaly would bring it all back to 0 whenever they felt like it. So why shouldn’t he just take what he wants? Enjoy what little he has?

_ What about him?  _ Sans slumped at the thought, guilt nearly outweighing even the intense lust he felt, even as his cock ached in his shorts,  _ you’ll hurt him. He’ll hate this if he wakes up, and you know it. Why is what you want any more important than what he wants? _

It wasn’t. Sans was just the only one who knew he could have  _ whatever  _ he wanted, regardless of how cruel or awful it was, and none of it would matter, irregardless of consequences. Like everything in his life, consequences were short-term and impermanent. He could take anything close enough to reach. 

And Papyrus was as close as he’d ever be.

This in mind, slowly, ever so slowly, Sans looped careful phalanges around the hem of Papyrus’s duvet and pulled, free hand gliding down towards his dick. He let his gaze rake over his brother’s clothed body as he tugged the comforter aside, cock twitching at the sight, eyelights blown. Fuck, this was disgusting, this was terrible.  _ This is rape. _

It doesn’t matter.

Papyrus’s legs, even through his clothes, were long, thin,  _ perfect,  _ the sharp, jutting edges of his pelvis outlined through his pajamas, the corner of his ilia just visible over the hem of his pants. Sans let a couple fingers graze over his own rapidly hardening cock through his shorts, just barely stifling a wanton moan at the minimal stimulation, hips rutting up into his hand.

_ Are you seriously this close, just looking at him? _

Yep.

He hurriedly tugged his shorts down, wrapping a tight fist around his cock and tugging, moaning softly at the shocks of pleasure that tore through his pelvis and his soul, eyelights bright and wide. This was the best he’d felt in ages, the  _ most  _ he’d felt in ages, the risk, the fear, the pleasure; it all came together in wonderful, crashing waves of adrenaline, tearing through his bones over and over as he jerked himself off, panting quietly.  _ You’re sick.  _

He knew.

After a few beats, slowly, much to his own chagrin, he pulled his hand, wet with magic and precum, away from his cock, soul pulsing rapidly within his ribcage. God, he was so close, already. Couldn’t cum yet, though. He had to do this the right way, exactly how he’d fantasized, how he’d planned. 

He’d tried staving off his disgusting, animalistic urges; stealing one of his brother’s sweaters here, a scarf there, keeping them hidden under his pillow until he was done with them. It was just about the only time he ever did the laundry. 

He’d jacked off nearly every night to the thought of Papyrus, of his  _ brother,  _ imagining him wet and hot and moaning underneath him, desperate for his big brother’s cock inside him,  _ begging  _ as Sans thoroughly fucked his sorry cunt _.  _ And,  _ fuck,  _ he couldn’t resist. He just couldn’t. The thought of his little bro squealing underneath him was too fucking much to supress. What a goddamn nightmare.

And here he was. Vulnerable and beautiful and alone, unconscious, helpless to stop Sans. Completely, totally helpless. And _ fuck _ if that wasn’t even hotter than he’d imagined. 

_ You don’t deserve him. You’re fucking disgusting. _

He reached out, fingers trembling, to tug at the hem of Papyrus’s pants, sliding the thin garment easily down and off of his pelvis, cock throbbing at the sight of his brother’s bare ilia, beautiful and angled and sharp.  _ Fuck.  _ Papyrus barely stirred, fingers clenching into weak fists for half a beat as Sans tugged his pants down even further, revealing his thin, long femurs, curved and bleach-white and perfect.

Sans watched Papyrus carefully as he crawled into bed, settling on his knees between the taller skeleton’s legs, eyelights never leaving his brother’s mostly unchanged expression. Good thing Papyrus was, apparently, a fairly heavy sleeper. 

A thick bead of precum rolled down Sans’s cock, which was seriously fucking  _ hard,  _ almost painfully hard, its head spilling bouts of slick the pure volume of which Sans had never experienced, not even during any of the many times he’d imagined this exact scenario. Jesus, this was a lot.

It was so, so good, though. 

He took a moment to glance down at himself, marvelling at the sight; he was  _ visibly  _ throbbing, the rich blue glow of his cock even brighter than it had been before, his length thick and full and long. He couldn’t fucking wait to bury himself in his little brother, hear him scream and cry, ruin his virgin cunt. 

_ Do you hear how you sound right now?  _

He leaned forward, resting one hand on the crest of Papyrus’s left ilia and letting the other travel deep into his huge, broad ribcage, grasping around for his soul. Papyrus’ brow furrowed, just a bit, as Sans caught hold of the compact organ, thick waves of arousal washing over him at the quiet moan that slipped from his sleeping brother at the contact.

God, he was _ beautiful. _ His high cheekbones were flushed, ever so slightly, mouth parted just a bit wider, now, brows creased and raised. His breathing sped up minutely, chest rising and falling a little bit more shallowly, hands clenching into weak fists. 

Sans, carefully and hungrily surveying Papyrus’s reaction, pressed down on his soul, digging his thumb into its malleable surface, pushing as much pleasure as he possibly could. A high, soft whine escaped Papyrus at the burst of sensation, his back arching sluggishly, hands clenching into fists. He didn’t wake, didn’t so much as shrug away, his cheeks burning a bright, soft orange, now.

Sans wasn’t sure he could get any harder.

He pressed down further, massaging soft, small circles into his brother’s trembling soul, quiet, soft moans tearing from between Papyrus’s gentle clenched teeth, his soul pulsing in Sans’s hand as he got his sleeping brother off. Much to Sans’ delight, a soft orange glow was slowly mounting between Papyrus’s ilia, magic swirling, formless, between his legs.

This didn’t feel real. He felt… separated, somehow, like a distant observer, watching himself rape his brother in his sleep, watching himself touch Papyrus’s soul, watching himself enjoy every fucking second of it. It didn’t feel like  _ him. _

But it was real. It was him, and it was too late to stop, now.

Sans rubbed at Papyrus’s ilia, eliciting soft, pitchy grunts from the taller skeleton, still massaging deep circles into his wettened soul. Sans wanted to look at it, wanted to watch his brother’s soul pulse and shake in his hand, but he wasn’t risking taking it out of his ribcage. That would almost certainly wake him, and it was too early, now, for Papyrus to wake up.

Sans, no longer able to help himself, rutted gently against Papyrus’s femur, desperate for some sort of friction, for  _ something,  _ watching with delight as his brother shied away from the new sensation. Fuck, he fucking loved the way his brother’s bones felt against his cock, loved the way his sockets squeezed shut at the touch, loved the quiet, keening moans that tore from him again and again as he kept at his soul.

Sans caught a glimpse of Papyrus’s ribcage under his pajamas as his chest stuttered with shallow, soft breaths, ribs thin and elegant and long, sturdy and strong even despite their narrowness. To think this was all that lied between him and his brother’s soul…

The thought was maddening, and oh so arousing. 

He let the hand on Papyrus’s ilia glide further down, past the solidifying magic nested in his pelvis and landing on his sacrum, drawing a soft squeal from the taller monster. He smirked, panting, cheeks burning with adrenaline and arousal and pleasure, eyesockets half lidded and sluggish as he watched his brother buck and rut down against his hand. 

Oh, god, he wanted this to last forever. He wanted to stay like this forever, rubbing his cock against Papyrus’s femur, massaging his soul, watching him moan and squeal and rut in his sleep, confused and sluggish and unsure. This was fucking perfect, this was so good, Papyrus was so, so good.

But then he felt a drop of Papyrus’s slick against his fingers, and excitement like never before filled his soul.  _ Jesus. You’re a fucking monster.  _

He withdrew his hand from Papyrus’s ribcage, inciting a soft whine from the vast skeleton, leaning clumsily back into a kneeling position to get a closer look at his brother’s cunt. 

Fuck. 

This was unreal. He was fucking  _ beautiful,  _ his plump lips a traunslucent orange, soaked with slick,  _ dripping  _ with it, clit swollen and throbbing beneath his twitching hood. He was an angel. A beautiful, sleeping angel. Sans wanted nothing more than to shove his cock into that tight little hole, watch Papyrus cry out and arch and beg, watch him  _ scream.  _ He was practically drooling, already, at just the thought. He wasn’t sure how he’d managed to go so long without this.

He didn’t care, anymore, wether or not Papyrus would wake up. He couldn’t care less, barely even considered it. He was throbbing, sick with need, with a want more intense than he’d ever felt in his entire life, mind blank and ravenous and racing. He needed this. Fuck, he’d needed this for so, so long. 

With that, he shifted, lining the thick, bulbous head of his dripping cock with Papyrus’s tight entrance, unable to withhold his moan at even just the simple contact, eyelights blinking out as shocks of sick, disgusting pleasure tore through his entire body. He couldn’t fucking help himself. He had about as much self control, right then, as an animal in heat.  _ You’re pathetic.  _

Papyrus mewled, frowning, inching away from the touch. Sans couldn’t have gotten more turned on. Fuck, he wanted this, wanted to watch his brother struggle and fight and cry, wanted to fill him up with his big brother’s cock no matter how hard he fought. What the fuck was wrong with him?

He didn’t care. It didn’t matter. He’d never wanted anything this much. 

About as quickly as he could possibly manage, he pushed his cock deeper, barely able, even, to breach Papyrus’s ridiculously tight hole. Holy fuck, holy fuck, that was so good, he was so  _ tight,  _ clenched and throbbing around him, warm and slick and perfect. Papyrus groaned, somewhere between pain and pleasure, eyesockets twitching as he danced the fine line between consciousness and unconsciousness. Sans  _ wanted  _ him to wake up. He wanted to hear him scream.

So he pushed deeper, cock throbbing and aching and twitching as his little brother’s tight walls clenched around him, surrounding him, magic seeping from the places where Sans pushed a little too hard, moved a little too fast, tore the sensitive ectoflesh that pulsed so tightly around his cock. 

He was nearly completely inside, and still struggling to push even further, when Papyrus finally woke up. 

Sans couldn’t even bring himself to feel shame anymore, watching hungrily,  _ ravenously,  _ as Papyrus blinked himself awake, chest rising and falling with panicked, sharp breaths, eyelights mere terrified pinpricks within his sockets as he struggled to grasp what was happening around him.

“Wh-” he squealed, crying out, as Sans managed to force the last few centimeters of his cock inside with a deep moan, Papyrus’s gaze confused and agonized and betrayed as it settled, at last, on his big brother.

“Br-broth-er-” he managed, tears building at the corners of his sockets, gasping, baffled, unsure what to do, what to  _ think, _ and it hit Sans, right then, that Papyrus probably didn’t even fucking know what this was,  _ holy fuck,  _ “wh- what are y-”

“Quiet,” Sans instructed, his voice a low growl, “and let big brother fuck you.” 

“Sans?!” Papyrus sobbed, struggling to process it all, the pain,  _ everything,  _ eyelights rolling into the back of his skull as Sans pulled out as far as he could and slammed, with no mercy, all the way back in, a pained shout tearing from the taller skeleton’s ribcage as his brother’s cock tested the limits of his cunt. Sans could only imagine the sheer terror and confusion he must be feeling right now, waking up to his brother’s cock buried in his pussy. Could only imagine the agony of having his tight, virgin hole fucked open for the first time. And, god, did he have a vivid imagination.

“St- wh-” Papyrus squealed as Sans grabbed hold of the undersides of each of his femurs, forcing his legs up and against his chest about as far as they could possibly bend, pushing himself deeper yet into his throbbing cunt. High, pitchy squeals and cries tore from Papyrus as Sans picked up a rhythm, an animalistic, brutal rhythm nonetheless.

Fuck, he was so  _ tight,  _ so wet, so easy. Wanton squelches rose above even Papyrus’s pained yells and sobs as Sans thrust as deep as he possibly could, over and over, hips digging into Papyrus’s ectoflesh with every ruthless thrust. Deep, rolling waves of pleasure, overlapping and intense, crashed through and over him, the best he’d ever felt, the  _ most _ he’d ever felt.

“Fuck,” he hissed, “fuck, Papyrus, you’re so good. God, you’re so tight…”

“Please!” Papyrus sobbed, reaching up with trembling, unsure hands, grabbing uselessly at his older brother’s t-shirt, “I d-don’t understand, st-sto-”

Papyrus cut himself off with a pained screech as Sans sped up, slamming into his brother over and over again, near-painful jolts of pleasure hitting him over and over as he fucked his sobbing, shaky little brother, revelling in his confusion, his innocence, his terror, deep, predatory grunts tearing from his chest as he thrust, desperate, like an animal. Like a disgusting fucking animal.

“It hurts,” Papyrus sobbed, pitchy, unintelligible, tears streaming down his face, and  _ fuck  _ was he beautiful when he cried, “it hurts! I d- I don-”

“Shut the  _ fuck up, _ ” Sans snarled, cock twitching as he grew closer yet to his orgasm, cheeks hot with arousal and adrenaline, “don’t you fucking speak unless I tell you to.”

Papyrus sobbed. Oh, if only Sans could slip into his mind, see what he was thinking, watch the terror and confusion play out in real time. He wanted to see so badly, wanted to hear his brother’s thoughts, wanted to know  _ everything. _

  
  


“I’m sorry,” Papyrus tried uselessly, eyesockets wide and terrified, cheekbones burning orange, “I’m sorry  _ pleasepleasesto-” _

Sans snarled, pressing deeper,  _ harder,  _ moving as fast as he could in and out of his brother’s gaping hole, pained, choked sobs and gasps the only sounds Papyrus could produce anymore. His ribcage was trembling, short, pitched inhales all he could manage through the agony he was surely facing. Sans was  _ close. _

He’d wanted this for so long, but he’d never imagined it would be this good. He slowed for a moment, still thrusting, deep, brutal ruts, eyelights raking over every detail of his brother’s expression, his terror, his wide, empty sockets, the orange-tinged tears endlessly streaming down his face. The humiliation and agony behind that deep orange blush, behind  _ everything _ .

The way he shook, entire body wracked with intense bouts of trembling. He didn’t know what to do with his hands; one second, his fists were buried in the sheets underneath the brothers, the next, he was batting at Sans, desperate, confused,  _ panicking.  _

Helpless. Completely fucking helpless and so, so beautiful.

“How’s it feel?” Sans sped back up, grunting, eliciting a pained whine from the overwhelmed skeleton beneath him, “my cock, filling you up?”

Papyrus sobbed, terrified expression laced with disgust and vague, tentative understanding, eyesockets clamped shut as he struggled, struggled through the pain, through the confusion, through his own humiliation.

“It  _ hurts, _ ” he managed, hateful, angry,  _ agonized,  _ “pl-please, I don’t…”

“No,” Sans growled, glaring hard at his younger brother, eliciting a desperate cry from the trembling monster, “no. Tell me you love my cock.”

“I-”

“Fucking  _ say it,”  _ he snarled, “or I swear to god I’ll fuck you so deep you’ll have my fucking  _ kids. _ ”

Papyrus sobbed in desperate terror, shaking his head, back arching sharply as Sans pushed deep inside his aching cunt. Oh, he looked so scared, so confused, so  _ lovely.  _

“I- I love y-” he choked on the words, burning up with humiliation and anger, “your cock,  _ please-” _

“Good, good boy,” Sans muttered, taking a moment to break away from Papyrus’s expression and glance down at Papyrus’s cunt, noting, with pride, the places where it’d been stained blue. His cock was coated in Papyrus’s slick and the spilt magic from the tears in his ectoflesh, a sickly, translucent orange. 

“Now,” he muttered, speeding up once more, a low, pitiful whine rolling from the back of his younger brother’s throat, “beg me to fill you up with my cum.”

“Don’t, don’t,” Papyrus chanted desperately, eyesockets snapping open, “please! Please, please d-”

“Don’t you fucking tell me no,” Sans hissed, thrusts growing irregular and desperate as he approached his climax, “beg me to fill you or I’ll fuck you till you dust, you hear me?”

Papyrus froze for just a moment, shock and terror filling his sockets at the prospect. He softened, eyesockets half lidded with exhaustion and embarrassment, another deep sob slipping from between his clenched teeth.

“Please,” he begged, shaky, “f-” he glanced away, squeezing his eyesockets shut with disgust, “f-fill m-me up with y-your-”

Before Papyrus could finish, Sans was gasping out deep, wanton moans, pressure building behind his soul, thrusts speeding up as he teetered at the edge of his climax, and-

“Oh,  _ fuck, _ ” he snarled, positively aflame with pleasure as he rode out his orgasm, deaf to the pained yells and sobs still tearing from his little brother as he finished, thick, hot ropes of cum filling his brother’s aching, tattered cunt, seeping into the deep tears in his ectoflesh. 

Sans panted, collapsing against Papyrus’s broad, shaking torso, cock still buried deep inside his brother’s aching pussy as he struggled for air. Fuck,  _ fuck,  _ that was so good. He’d been so, so good.

“Good boy,” Sans muttered, ignoring the pained, quiet sobs from the taller monster, “you were so good, Papy.”

“S-Sans?”

He startled, grin fading, eyelights flickering as he moved to meet his brother’s gaze.

Oh.

Papyrus looked  _ broken,  _ thoroughly, completely broken, eyesockets wide and empty, terrified, expression contorted with fear and confusion and betrayal. He was shaking, hard, tears still streaming endlessly down his face as he stared at Sans, desperate for answers, desperate for  _ something.  _

_ Oh. _

_ Look what you did. Look what you fucking did to him.  _

It doesn’t matter. None of this matters. He won’t remember for very long, and you know it. It’ll all be reset soon enough, he’ll be reset soon enough and we’ll both forget this ever even happened. It doesn’t matter. 

It shouldn’t matter.

Papyrus sobbed weakly, terror and confusion and betrayal all that was gatherable from his horrified gaze, his eyelights mere pinpricks within his eyesockets, high, shrill sobs still slipping from between his teeth. Trembling underneath his older brother. 

Oh, god.

What had he done?

**Author's Note:**

> i hope it was fun!!


End file.
